This article explains the motivation, design, and implementation of a real-world business approach to teaching managerial accounting in an M.B.A. program to facilitate a shift in student learning from traditional passive listening to active participation. A teaching methodology requiring students to work through the evolution of a potentially viable business contributes to a long-standing effort in the profession to link practice and theory. The course immerses students in the life of an evolving business in four ways: working assignments based on lectures, discussing costing concepts individually with the instructor, summarizing existing research papers, and most importantly participating in mutual interest groups to develop a realistic business plan based on personal research. This approach integrates learning of cost concepts with developing critical thinking skills. It differs from other student projects because students may choose a business based on interest in any industry, and the instructor provides no cost or industry data. Anecdotal evidence indicates that this approach works to stimulate student learning. This paper also addresses some limitations of this approach.